Remove some exists checks by not validating

lib/Cake/Model/Datasource/Session/DatabaseSession.php

@@ -119,9 +119,9 @@ class DatabaseSession implements CakeSessionHandlerInterface {
 		$record[$this->_model->primaryKey] = $id;
 
 		try {
-			return $this->_model->save($record);
+			return $this->_model->save($record, array('validate' => false));
 		} catch (PDOException $e) {
-			return $this->_model->save($record);
+			return $this->_model->save($record, array('validate' => false));
 		}
 	}
 

lib/Cake/Test/Case/Model/Datasource/Session/DatabaseSessionTest.php

@@ -213,31 +213,16 @@ class DatabaseSessionTest extends CakeTestCase {
 			->method('exists')
 			->will($this->returnValue(false));
 
-		// First validate
-		$mockedModel->expects($this->at($counter++))
-			->method('exists')
-			->will($this->returnValue(false));
-
 		// Second save
 		$mockedModel->expects($this->at($counter++))
 			->method('exists')
 			->will($this->returnValue(false));
 
-		// Second validate
-		$mockedModel->expects($this->at($counter++))
-			->method('exists')
-			->will($this->returnValue(false));
-
 		// Second save retry
 		$mockedModel->expects($this->at($counter++))
 			->method('exists')
 			->will($this->returnValue(true));
 
-		// Second validate retry
-		$mockedModel->expects($this->at($counter++))
-			->method('exists')
-			->will($this->returnValue(false));
-
 		// Datasource exists check
 		$mockedModel->expects($this->at($counter++))
 			->method('exists')